As LEDs are being introduced into wide areas of general lighting, there is a major requirement for simple and low-cost power supply circuits for these components. One converter circuit which is known for operation of LEDs for mains applications is the so-called flyback converter. Furthermore, there are now a multiplicity of in particular integrated circuits for Buck or boost converters, for example the MXHV9910 control IC from the company Micronix. These embodiments have the disadvantage that they all require quite considerable complexity and the use of expensive components. By way of example, the switch in a flyback converter for the European mains voltage must have a withstand voltage of at least 700 V. The costs that this results in frequently exceed the budget provided for use in mass-produced products.